Arrangement of radially traversed blades in rotary machines



21, 1937.- u` MEININGHAUS 2,102,637

'ARRNGEMENT OF'V RADALLY TRAVERSED BLADES N ROTARY MACHINES Filed May17, 1935 6 Sheets-Sheet 1 l W ,u

k r f va Hrm/mfr Dc. '21', 1937'. U. MEININGHAUS v 2,102,637

ARRANGEMENT OF RADIALLY THAVERSED BLADES IN ROTARY MACHINES Filed Mayx7, 1955 6 sheets-sheet 5 Fig 3 m f :ELi ,2

dz, 5- o a S IMI Y d w m 1.." I` Y a l 2- 6 i, 6 m III/ /III/l IIIII 63. la y9 23 fr* 8 l/rwfrfrolil l21,. 1937. U MEININGHAUS Y 2,102,637

ARRANGEMENT OF RADIALLY TRAVERSED BLADES IN ROTARY MACHINES Dec. 21,1937. u. MEININGHAUS 102,631

AARRANGEMENT OF'l RADIALILYl TRAVERSED BLADES IN ROTARY MACHINES v'FiledMay 17, 19253 6 vSheets-Sheet 5 Dec- 21, 1931- U. MEININGHAUS 2,102,637

- RRANGEMENT OF-RADILLY TRAVERSED BLADES IN ROTARY MACHINES 6Sheets-Sheet Filed May 1'?,` 19:53

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/M nr B KMF/ 'Paie-mcd Dec. g1, 1931 UNITED s'iisxri'is My inventionrelates to rotary machines such as steam or gasturbines in which 'aworking medium ows through aplurality of blades yin a radial direction,varying in pressure during such iiow. 'I'he object of the presentinvention is to' diminish the total axial thrust created by thevariation of pressure with which the working mediumacts on radiallyextended surfaces and at `the same time to improve the conditions ofVilow.

It is known that in rotary machines provided with reaction blading largeaxial thrusts occur which are generally equalized by subjecting anequalizing pistn provided with packing to an .Y

oppositely directed pressure of the working medium. As the packings ofthe equalizing piston must-be arranged on a large diameter in order toexpose suihcient piston surface to the pressure the packing loss, whichis at least proportionaly to the packing diameter, is large. In the con-I chine is, therefore, lengthened. On the other hand, a construction ofthe shaft with small blading diameters does not permit of great lengthoi A the shaft in view of oscillations, in particular in view cfcritical speeds cf rotation. Extension and thinning of the shaft,therefore, have an unfavourable effect. A limit isfthus very soonreached 'in applying these known means for reducing clearance losses ofthe equallzing pistoni In cases of rotary machines with multiplehousings the additional losses of the equalizing piston have beensuccessfully avoided by letting the medium traverse the several housingsin op` posite directions', the now oppositely directed thrusts on theshaft being determined in such practically counterbalance one.

l a way that they another.

'Ihe absolute thrusts on the '-shafts remain, however, large. Even smallvariations from the calculated values give rise to considerabledifferences in thmst which must be taken up by the thrust bearing andmay destroy it. In particular,.

the thrusts exerted on the shaft change to difterent degrees whenoverloads occur, or when some aimerail ARRANGEMENT 0F RADIALLY`rIRAVERSED BLADES IN ROTARY MACHINES Ulrich lVI-eininghaus,Mnlheim-Ruhr, Germany f Appiicaticn May 17, 1933. scr'ici Nc. 611,442

- In Germany June 1, 1932 .15 claims. 4 (C1. 253-19) PATENT loF'r'lcF.

of the working medium is tapped off. If the absolute axial thrustsexerted on the shafts are considerable, such. large difference in theoppositely directed thrusts may arise in such cases that the thrustbearing can no longer withstand them or at least is likely to beendangered. Fur. thermore, such an arrangement involves large demands inspace and high costs in manufacture.

Stilllmoreunfavorable was the position in regard to the previouslyproposed constructions of radially traversed rotary machines. In orderto obtain as simple a construction as possible or in order to allow the,diameter of the blading to increase progressively in accordance withthe expansion of the working medium during the flow through the rotarymachine, it was attempted to arrange the blades on as few discs aspossible as far as was permissible in viewof the avoid'- 'ance ofoverloading, by centrifugal force, of the double housing was'applied.one disc for each of the opposed housings. the discs carrying theblading were inbthis way large, and, therefore, the axial thrust assumednon-permissible values. The above described disadvantages. therefore.were particularly conv spicuous in theconstruction of radially traversedl rotary machines.

According to my invention, I proceed from the conception that thesedisadvantages which occur particularly in the construction oi.' radiallytraversed rotary machines are based on the fundamentally incorrectattempt to provide as many blades as possible on as few discs aspossible, and I propose in contradistinction thereto to employ. thesaving in axial-length resulting from the radial arrangement of theblades for arrangingas many radially traversed blades as possible on thesmallest `possible mean diameter. According to the invention, I attainthis-object by distributing' known to be necessary for avoidingoverstressing by centrifugal force of the outermost rotating' bladesorthe devices supporting them-or for producing oppositely directed axialthrusts. In such an arrangement I dispose only comparatively few bladeson a bladed disc. The diameters of therdiscs are thus kept comparativelysmall, vso that the-surface offered to thepressure of the working mediumand, therefore, the absolute thrusts exerted on the discsremain small.In

The mean diameters of a selected quantity of radially traversed reactionv'blades among aA larger number of discs than is 2 this way it issurprisingly easy'to diminish the absolute axial thrusts, or to maintainthe differential between oppositely directed thrusts within safe limitsand thereby avoid any danger to the thrust bearing.

By the reduction in blading diameter the further advantage is obtainedthat small speeds ,of `flow of the working'medium can be advantageouslyemployed and that the hydraulic losses are greatly diminished. It isknown that small speeds of flow themselves result in smaller ilowllosses;l in addition however the blade channels turn out largerthemselves in consequence of the diminution of the blading diameter(diminished periphery) and alsoin consequence of the slowing down of theflow whereby the edge losses and clearance losses diminish comparativelygreatly.

On the accompanying drawings, are shown diagrammatically and by way ofexample various constructions according to the present invention in itsapplication to steam turbines. All of the figures of the drawings showvertical sections along the middle axis of the turbine shaft. In saiddrawings,

Figure l shows a multi-stage condensing turbinek working with high headbut with normal quantities of steam, theblading being distributed vonthe two shaft ends of another rotary machine,

for example a generator, so as to equalize the thrust; l

Figure 2 shows an arrangement similar torFlgure l but for larger steamquantities, and involving a duplicated arrangement and paralleltraversal of 'an aidally traversed blading and the immediately precedingradially traversed blading inl the lowest pressure stages;

Figure 3 shows the arrangement of all the blades of a'condensing machineon one end only of the shaft of another rotary machine, the labyrinthdisc provided for equalization of thrust being arranged close to therotating wheel which carries the axially traversed blading and in viewof its weight is disposed near the bearing;

Figure 4 shows a 'solution which lies betweenthe solutions shown inFigures l and 3 in. that the one shaft end of the driven rotary machinecarries all the blading and the other shaft end the equalizing discs;

` Figure 5 shows a condensing turbine in whichv the 'steam pressure isrst reduced in a Curtis blading to s uch yan extent that with thereaction blades disposed according to the invention the total thrustdoes not overload the thrust bearing;

and

Figure 6, finally, shows a turbine with a separate shaft carrying allthe discs between the bearings of said shaft and provided with a colt--pling to drive another rotary machine.

In Fig. 1, the parts marked I represent the bearings which carry theshaft 2 and are arranged in the housings 3. The packing between theturbine and bearing housings is effected by the labyrinth packings l.Certain leakage quantitiesescape for example through the pipe l.'Iheshaft ends 2 are extensions of a shaftwhich carries a rotorofl adriven rotary machine, for example a, generator (not shown) The free`shaft ends of the shafts 2 carry a plurality of radially traversedbladings ci, an, aa, 'a4 etc. The

rotary part of this blading is carried by the discs b1, bz, bs, b4 etc..and the stationary part by the disc ci, ci, egel etc. As may be seenfrom Fig. 1, the bladesof the above mentioned radially traversed bladingare distributed on a large number of discs and the number o! rows' ofblades of `stages because the greatest head is here trans? diameters ofthe last traversed blades of the disc 5 ba as such blades-possess-themaximum blade lengths and therebyv the greatest centrifugal forcestress. Smaller diameters are, however, preferably chosen for theother'discs, especially for discs a1 to a5, which are traversedby steam1 of high pressure and which create .the greatest axial thrust,- inorder to keep the axial thrusts small. I'he blades are thereforedistributed 'on a larger number of discs than would be necessary by thegeneral use of such large outsidedi- '1 ameters as arepossessed by thelast traversed blades ofthe disc bs, the-number and size of the rotatingdiscs being such that the blades of at least one ofthe discs can bedistributed in the distributed on a number of discs.

It is important for the effective'reduction of the axial thrust and forsimultaneous maintenance of good conditions of iow that a substantialproportion of the reaction blades should be traversed from the inside orthat blades distributed among a number of `discs should be providedwhich are traversed in a radially outward direction. It is known to beadvantageous to transform a larger head in the rows of blades ywithincreasing peripheral speed o i the blades. The outermost rows ofblades of the radially traversed blading therefore transform a largerhead than the inner rows. 0n the other hand, a I

larger drop of pressure accompanies a given head a,

of Woking medium with higherpressure of the working medium. Ii'therefore the blading is traversed radially from outside to inside thelargest drop in pressure is produced in the outermost# lform oi'additional rows on at least certain of 20 formed and because at the sametime the works ing medium on entering from outside l outermost rowsofthe blades possesses the highest pressure. In the 4inner rows of bladesthe` head transformed diminishes and also the pressure of theworkingmedium whereby the drop in pressure effected by both influences .isdim-inished; 'I'he described inuences have a reverse eifect on eachother and, therefore` act in the sense of the equalization of pressuredifferences in a blading traversed from inside to outside. However, thesurface oiferedto the pressure difference of the working medium islarger in the outer rows ofblades, corresponding tothe greaterperiphery, than in the inner rows of blades, so that an increased dropin pressure towards the outside results in an increase in the totalthrusts vwith the same total pressure drop. A blading into th*progressive expansion of the working. medium.

- direction.

The discs b1 to ba and ci to en, on which radially traversed bladesaccording to the invention are disposed, the pressure being different inat least each second row of blades, are arranged axially one behind theother, i. e., they are .traversed consecutively by' the working medium.In consideration of the great advantages ofthe outwardly directedtraversal, and also with regard to diminishing theheat exchange throughthe discs, only one slide of the surface of discs disposed between otherdiscs carries radially traversed blades, the interspaces between theunbladed disc sides of adjacent discs servingfor returning the workingmedium. 'I'hus by the exclusive or nearly exclusive use oi' bladingtraversed radially towards the'outside only one side of the Idiscs bi,bz, bs, b4, etc., and of the discs ci, cz, ca, c4, etc. is bladed,whilst the steam returns on the rear side of the discs from the outerperiphery towards the center.

As 'according to my invention oftenv as many discs as possible are to beprovided on one shaft, it .is vof extreme importance that stationaryand, rotating discs which carry radially traversed blades should be ofaxially, undivided construction whereby erection andrremoval take placeinaxial were axially split -inv order to permit of inspecting the bladesby simply lifting off the upper halves of the stationary blade carriersas is customary in the construction of axially traversed i' turbines,there wouldbe a quite' substantial limitation inthe possibility ofaccommodating the dlcs. The axial'split line ofthe discs involves a veryconsiderable weakening of the discs as tangential stresses which in themain are producers of stiffness of the discs can no longer formundisturbed but are in the main relieved by the axial joint. Discsprovided with an axial split line, therefore, have to be constructed ofgreater thickness, which construction, in the case of a plurality ofdiscs, results in a substantial increase in theleng'th'of construction.Moreoven the provision of an axial joint in the stationary discs is onlyadvantageous. when, as describedabove, a`

provisionk of axial joints in the attachment of Vradially traversedblades has further constructi'onal disadvantages which are particularlymarked when the free blade ends are supported by carrier rings as hasbeen .shown` to be necessary in practical successful constructions.-Therefore also the stationary discs' c1 to ca are all of integralconstruction so that tangential forces arising from the axial thrustscaused Abv* the steam pressure, resist distortion of the discs.

I have obtained a particularly compact con 'struction ofthe discsbi tobs and c1 to cs by ar-I ranging the parts in such manner that theradially traversed blades a1, a2, as, a4 etc. -are supported bytangential annular elements or rings.

a' of closed construction which are connected on one side with theblades byconnecting webs to form thin thermally flexible discs, theaxial thickness of the webs not exceeding or not appreciably If, forexample, the stationary discs exceeding the .radial thickness of thecarrier ring, asv described and claimed in my copending applicationSerial No. 600,500. By thermally ilexible is hereby to be understoodthat no special linkages between the carrier rings and the discs, -whichwould increase the axial length, are necessary in order to allow theaforesaid carrier rings a capacity of expansion or contraction on changeof temperature of the working medium which is practically as great asthat possessed by the carrier rings which are connected only to theblades. Such thermal flexibility of the vcarrier rings is necessary toobtain minimum' packing play within the blading. By diminution of theaxial thickness of the discs, therefore, a diminution of axial length iseffected in adouble sense and multiplies itselfcorrespondingly by theprovision ofv a plurality oi discs and thereby renders possible theaccommodation of this plurality of discs.

so thin that with minimum axial length they can at once follow allvariations in the thermal condition of the steam, so that theinterposition of special flexible connections between the carrier ringsand the discs is superfluous.

It appears at iirst as if the blading diameter of the axially juxtaposeddiscs could not be sufllciently accommodated to the increase in volumeof the working medium. I have found,` however,

that surprisingly good results are obtained by a'- blades. In this wayit is possible to fix each discV for itself, e. g. by caulking, as thelarger discs can be slid into position undisturbed over the supportingshoulders for the smaller discs.

The mean diameters of the bladings a1, az, aa,

a4, etc. are therefore made to increase from disc to disc in thedirection of fiow and accommodate themselves satisfactorily thereby,with simultaneous increase in the steam speed, to the increase in steamvolume. Likewise, the internal diameters of the discs increase from'discto disc and thereby it is rendered possible to provide on the bushes 1,carrying the rotating discs, shoulders 6 which are necessary for takingup the axial thrust of the rotating discs b1, bn. bs, tu.,

etc. but which do not prevent movement of the discs axially into placealong the bushes,

The subdivision of the radially traversed bladesy among a larger numberof discs does not "exclude the increase of the vdiameter onwhlch theHence the discs are rigid against thrust but can be made outermostblades of the last discs in the direction of flow of the drivingmediumare disposed to a.

limit which appears permissible in view of the stresses due tocentrigufal force when, for exaxially traversed blading. In view of vthesubstantial weight of rotating wheels which must support such axialblading, I prefer to arrange the rotating wheel carrying the axiallytraversed blading between a bearing and the radially traversed discs inorder to relieve theshaft.

In-Fig. 1 the external diameter of the last radially' traversed disc bsis extended up to the limit which appears permissible in .view ofcenview of the large steam volumes.

trifugal stress. The large surface of these discs has practically noiniluence on the magnitude of the axial thrust, as the steam pressurehere is already very-low. 0n the other hand, a large blading diameter ismuch desired in this place in The volume in the last low pressure stagesof the turbine is already s'o large that an axially traversedlowpressure blading 8 is provided. The rotating blades of this low pressureblading are arranged on a rotating wheel 9 and the stationary blades onan axially divided ring Il). The heavy rotating wheel il isidisposed, inview of the load on the shaft end due to its very great weight, betweenthe bearing l and the radially traversed discs be, b1 and bs. I

Fig. l shows an overhung arrangement of the radially traversed discs h1,bz, ba, b4, etc. on the shaft ends 2 of the rotary machine (not shown)e. g. a. generator. Quite special advantages result fromV such overhungarrangement of the radially impinged discs on the shalt ends of ro tarymachines, for instance, packing oi the shaft against thefull pressure ofthe working medium maythen be completely avoided. I'he most valuablemachine results, however, when radially impinged discs are disposed-inan overhung manner on both'sha'it ends of another rotary machine asshown in Fig. 1. The opposed'construction as described above for axiallytraversed rotary machines can then .be employed and all packing againstfull working pressure can be dispensed with, but notwithstanding, a,disproportionately large number of radially traversedblades areaccommodated on a number of axially juxtaposed discs whereby theabsolute axial thrust is kept within permissible limits.

The overhung arrangement of the discs involves the further advantagethat a simpler, cheaper and more compact total construction is obtained.The enclosed machine unit can be supportedr in the simplest vway---forexample in case of steam tur.bines-on.the condenser and can lthereforeoften be shipped in the built-up condition whereby substantialfoundation and working costs are saved. In particular there is nocoupling up of separately journalled power transmitting shafts and thesingle shaft which is supported in two bearings only can be balanced soas to be practically free from oscillation, such condition not beingdisturbed by any coupling with powertransferring shafts.

The same idea of diminishing axial thrust can be applied to the packingsbetween working medium and bearing oil. To this end I arrange thatcorresponding to the axial juxtaposition of the radially traversed bladecarrying discs the packing devices, which in known manner possessradially arranged throttle positions,A should consist of several axiallyjuxtaposed discs.

The labyrinth clearances in the steam packing l are accordinglydividedamong several rotating discs di and d2 as well as stationarydiscs ci, en.. in order to keep small the axial thrust of these discs.

In Fig. 1 the rotating discs b1 to ba are distributed upon the two shaftends 2 of a rotary machine'for reasons above described. The steam entersin the high pressure housing I I at l2, iiows consecutively from theinterior outwardly through the blades a1- a5, and leaves the housingagain at I3. The pipe line I3 leads the steam into -pressure discs.

vcreased in this manner.

bearing.

the bearings and radially impinged discs.

amasar the low pressure housing il, and the steam ows consecutivelythrough the bladings as, a1, as, and

8 and finally escapes through the exhaust steam pipe L. As the steampressure decreases within.

the bladings a1, m, as, ai, etc., a lower pressure is exerted on therear sides of the rotating discs b1 to br than on the bladed sides oi'the discs and 1 discs, arises which is equalized through the housing ofthe rotary machine (not shown). Any differences in thrust which arisevare small as the absolute values of the axial thrusts are small inconsequence of the small diameter of the high taken up by the' thrustbearing (not shown) -of the rotary machine, such as a thrust bearing ofthe type shown at 21 in Figs. 4 6.

The above described devices concern principally discs with radiallytraversed blading, which are juxtaposed axially and traversedconsecutively by the working medium. The stated constructions meetdiiliculties, however, when driving media of'very large volume are Itobe operated with, in particular in the construction of the low Ypressurebladlng. Itis known to reduce the blade lengths necessary'for operatingwith driving media of. large volume by arranging that the blade groupsare multiple and are traversed in parallehaxially traversed blade groupsbeing conveniently disposedv after radially traversed blade groups, asthese can be constructed with larger admission diameters.

Parallel traversed blade groups in the case of radially traversed bladeswhich, as is known, are advantageously supported at both ends by closedcarrier rings, can be amplified up to certain limits by the provision ofblade rings additional to the yhead rings of blade rings alreadysupported on one sideyof the blade carriers.. T'his'juxtaposition ofblade rings soon reaches a limit, however, in viewof thedanger ofoscillations and of overstresslng by the sum of the torques. Besides,the blade length of axially traversed blade groups which. as shown inFig. 1. sometimes followthe radially traversed blade groups cannot bein'- One is therefore compelled to arrange separate blade carriersparallel to one another and to provide between them the necessary spacefor the inflow and outilow of the 4 They can without danger be shaft endas those blade groups which must operate with driving-medium of largevolume, and consequently'possess large diameter, considerable bladelengths and large weight, must be arranged in the immediate neighborhoodof the bearing in view of bending and critical speed` of revolution ofthe shaft end.- 'I'he parallel larrangement of such blade carriers ononeand the same shaft end would-result in non-permissible wide spacing ofVat least one of the blade groups from the In a further development ofthe invention I therefore propose that rotating wheels carrying axiallytraversed blading be arranged on both shattends of another rotarymachine between Ihe axially traversed bladings are then traversed inmedium possesses high pressure and small vol-,

parallel in known manner, Hereby one half of two parallel blade groupstraversed in radial directio'n can be disposed in iront of each of theparallel blade groups which are traversed in axial stages are disposedat the' rear of similarly divided.

and parallel traversed radial stages.

It is not advantageous in the case of rotary machines which are to beoperated 4with a normal total head of the driving medium, to constructboth sides completely symmetrical, i. e., to divide all the bladegroups. 4and to traverse them all in parallel. Not only would in thiscase the blade length be small and the clearance losses great in thoseblade groups in which the driving urne, but it would above all bedifilcultto accommodate on each side the total number of stagesnecessary for satisfactory utilizationv of the full head. It istherefore important .to employ the double flow, i. e. the parallelarrangement of ythe blade groups in the region ofgreat volume of 4theworking medium, i. e. preferably in the region of low pressure, and inthe remaining part of the blading on the other hand to employ the singieflow with provision of as many consecutive stages as possible. In vicwof the great importance of this task, .I construct the apparatus in sucha way that the blade groups which are first traversed by the workingmedium entering the machine are arranged near the one half of theparallel traversed blade groups on the same shaft end, and that theblade groups traversed next by the working medium flowing out of theabove bladc groups are located near the other half of. the paralleltraversed blade groups on the other shaft end. In this way, I obtain thebest possible distribution oi'. theblade groups in relation to bendingVand critical speed'of the. shaft end, as

now the heavyblade .groups which operate with" driving medium of largevolume can be disposed in the immediate neighborhood of the bearings,whilst the preceding light stages are located at theends of the' shaftwhere they may be provided in greater number inconsequenceof their lightweight.

In order to be'able to dispose the so arranged blade groups in series inllarge number at the beginning of the transformation of energy of' theworking medium and in parallelat'the-,end

of the transformation of energyI propose, as a'.

further development of my invention, to carry out the operation in sucha waythat the total working` medium as far as it transforms-its fullenergy in the rotary machineis led after partial the driven rotarymachine to the other shaft end,

transformation of energy from one shaft'end of and that a part of theworking medium after further, but not yet complete transformation ofenergy fiows back again to the iirst mentioned shaft end, whereby theremaining transforma' .tion of energy of the Working medium takes placeat both shaft ends. .A tapping off, if such is requiredfisl neglected inthe above description. One` emodiment of this form of my invention isshown in Fig. 2 which is diierentlated from Fig. ^1

pressure housing Il. Here the whole mass ofl steam iiows through only.the bladings ai and as whereupon only one 'half f the steam traversesthe bladings as and 8 whilst the other half lis y led back to the highApressure housing Il through the pipe IG. This steam then traverses thebladings a1 and 8a, i. e. the bladings as and a1 as well as the bladings8 and 8a are traversed in `parallel by steam of the same pressure asotherwise the blade lengths would become very large in consequence ofthe large volume of steam. Between the steam leaving the bladingaa andthe steam entering the bladiug a7 a packing l1 must naturally be pro-'vided which is vconstructed of packing clearances distributed on discs.The steam iinally iiows away through the two exhaust connections I5 andlI5a. V

The arrangement shown in Fig. 2 hasthe particu- `lar advantage thatthebla'dings a1, a2, as, a4, and as traversed by steam at high pressurepossess a low traversal diameter in consequence of the axialjuxtaposition of the radially traversed discs b1, b2, ha, b4 and b5, andthereforesmall axialy thrusts and large bladel lengths are realized,whilst in the region of 'low pressure, on the otherhand;`

bladings as, av, 8 and 8a traversed in parallel by large steam volumescan come into use, This ensures favorable distribution of weight andequalization of thrust. 'In other respects, all that has been said inconnection with Fig. -1 applies just as well to Fig. 2. 'It applies alsoto the following Figs. 3 to 5 with the exception that in these figuresall blades are arranged lon one and the same overhung' shaft end andthat the axial thrust is equalized i-n different ways byspecialarrangements.

. .The advantages of diminution. of the absolute axial thrust bythedisposition of the radially irnpinged .discs` in series according tothe inventionl arise also when the axial thrust is equalizedby speciallabyrinth pistons or labyrinth discs. If, however, the advantages are tobe 'fully realized,

great care must be taken that good packing con`` I ditions exist for thelabyrinth pistons or discs. It is important to keep small the overhangof the free shaft vend of the rotary machine as this exer-i cises greatinfluence on they possibility of maintaining the extremelyiine packingplay. Even in a two bearing system, such as is obtained by an inproportion tothe distance from the bearing centre and produce,therefore, with increasing overhang an increasing wearon the packingpoints and, thereby, an increasing enlargement of the packing play whosemaintenance at low values on the other hand is of extreme importance forthe attainment of high eilicien'y. In recognition of this fact, ithasalready been proposed to dis? pose the parts which are most sensitive inregard to the maintenance' of packing play as close as possible to abearing. In machines with a vpressure equalizing disc this applies first-to such 5 disc, furthermore to the high pressure stages in which thevolume oi' the working medium is still small. With decreasing pressure,i. e. increasing volumeythe harmful effect of a possible increasingclearance diminishes more and more. In machines in which axial thrust istaken up by a pressure equalizing d isc provided with labyrinths,therefore, an arrangement of 'the pressure equalizin`g disc in theimmediate neighborhood ofthe journal has proved of value, the drivingmedium flowing to thevblading in the direction from the medium possessesalready vthe greatest volume is then located further distant from thebearing.

In rotary machines with very. large iinal` volumes in which the laststages must be carried out withaxial traversal, such an arrangement hashitherto Yappearedimpossible. Ihe wheel carrying the axially traversedlow pressure stages is'so harmful bending of the shaft end is to beavoided. As an example of such a case, steam turbines for condensationoperation may be mentioned.

In a further development of my invention I provide a new arrangementwhich permits of disposing the pressure equalzing disc and low pressurewheel in close proximity to the bearing. Ihis arrangement consists indisposing a pressure equali'zing disc with axial thrust in the'direction towards the bearing next to the rotating wheel which isarranged between the bearing and the radially'i'mpinged discs andcarries the axially traversed blading so that the equalizing disc islocated-between axially and radially impinged ldiscs or rotating wheels.This arrangement involves the further advantage that the rotatingequalizing disc, which.' is constructed with very thin walls owing tothe required thermal flexibility, lies against the rotatingwheelcarrying the axially traversed low pressure blading, so that the axialthrust is transferred from the equalizing disc to the rotating wheel. Aspecial support for the flexible equalizing disc can be dispensed withas the very strong rotating wheel can take up the axial thrust withoutbeing overstressed. A

lIn Fig. 3, therefore, in contradist'inction to Figs. 1 and 2, all theblading parts and devices forequalization of thrust are disposed on oneoverhung shaft and only of arotary machine (not shown). Here again theradially traversed bladings ai, az, as, and a4 are arranged in axialjuxtaposition and behind them is disposed an axially traversed blading8.. One of the novel features of the construction of Fig. 3 is thethrust equalizing discs I8`a and lab with the labyrinth |81 In order togive these a minimum overhang-distance from the bearing I-they aredisposed immediately next to the heavy ,rotating wheel SI carrying theblading B which for its part is arranged i'acing the bearing inconsequence of its large weight.

A so-calledregulating stage (action stage) for improving the part-loadeiIlciency may be disulatin'g stage as a radially traversed stage and`posed in front of the' high pressure reaction` blading, but the spaceavailable for this purpose with normal constructions is not sumcient.The

v space required for axially directedv inflow. and

outiiow of the working medium is too large. In order torender possiblethe arrangement according to the invention I provide, therefore, theregobtain the space for the provision of the equalizing discs Ita andlbbetween the high and low vpressure wheels. In this way there 'resultsout' side the actionwheel also suilicient space for a correspondingarrangement oi' the nozzlel groups 2Il without the axial length needingto be increased to a non-permissible extent. The quantity -of workingmedium flowing out iiows inwardly directly to the first radiallytraversed high pressure stages al which are traversed from outwardsinwardly and are advantageously arranged within the action stage 22.

As the working medium leaving the high pressure blading a4. vat the freeend 'of the shaft in consequence of its great volume is led to the lowpressure blading 8 through conduits 23 which surround theI Whole machineas a closed ring, special measures are necessary to lead the live `steamto the equalizing ldisc and highfrpressure time to the highpressureportion through pipes heavy that it 'is disposed/near to thebearing if I9 which are disposed elastically in a space inside thehousing Il through which flows the working medium iiowing to the axiallytraversed llow pressure ublading. Suchpipes can easily be fitted in apressure tight manner in the walls. As these pipes, however, aretraversed by a hotter medium than the space through which they pass,particular care must be taken that the considerable lare to be led.-This arrangement ensures with certainty avoidance of distortions andbending ofV the housing or the walls in consequence of unequal thermalexpansion such as would have occurred if the working medium had been ledto the high pressure portion through cast-in channels.

In Fig. 3, the steam enters the cbnduits I! through pipes I2 and ilowsthen into the nozzle chambers 20. regulations several separate nozzlechambers 2II For effecting the known nozzle are provided; From them thesteam flows through nozzles 2I to an action stage 22 which is traversedradially inwards and is supported by the disc b1, and thus space yisgained for the provision of the thrust equalizing discs lia and IIIb.'I'he steam flows through the blading a1 from the exterior inwardly,then from the interior outwardly through the bladings az, as, a4, and isfinally led through channels 23 p astthe pipes I9 "to the bladingj 8. 1-It leaves the machine through the exhaust port I5. Considering the axialdirection, therefore, the flow of steam through the bladings a1, an, as,a4 is opposed to that through the blading 8. In this way it -is possibleto compensate for the axial thrust on the radially traversed discs b1,bz, b3 and b4 which outweighs the axial thrust of the rotating wheel 9by a thrust equalizing disc I8a 'disposed on the rotating wheel. Thediscs b1, b2, b3, b4 are arranged on a' common bush 1 in order to rendereasily accessible the equalizing discs I-Iia and Ib of the labyrinth I8.This arrangement is chosen as the diameters of these discs increase incorrespond- Special cases sometimes arise in which on the one hand theaccommodation of the pressure equalizing disc on the same shaft end'asthe discs arranged axially behind each other between the latter and thebearing, has disadvantages or causes diiliculties, but on the other handthev equalization of thrust by distribution of the bladed ence with thegrowth in volume of the working medium with the distance from theequalizing discs on both shaft ends ofV the rotary machine does notappear jjustii'led from economical considerations or meets technicaldiillculties in construction. For example, in case of large quantitiesof working medium the transfer npipes, which must c'onvey the totalworking medium from the one side to the other side after-.it isincreased in volume to a large extent by expansion in the first housing,assume considerabledimensions.A These large pipes which in practiceelongate differently from the rotary machine over which they bridge', lexercise considerable bending forces on the whole construction and mayin certain circumstances Acause disturbing displacements.' Specialexpansion pieces must therefore be provided which must possess, togetherwith sumcient power of resistance to the high pressure' of the workingmedium, also suillcient resilience. Sometimes space is lacking for theaccommodation of the large transfer pipes. Finally, in many casesintermedi- -ately arranged auxiliary' machines hinder the transferenceof large torques of the rotary machine from or to both shafts ends. Alsothe packing of the shaft against the exit pressure of the high pressurehousing may involve perceptible losses in working medium. -In addition,disadvantages or difficulties can arise from the accommodatlon of thepressure equalizing disc between the bladed discs and the bearing insuch special 'driving medium as is necessary tov cqualize the.

axial thrust which is produced from the bladepor-,. tions disposed onlthe other end of, the. shaft..-l "f Furthermore, both ends of the shaftare to be cases. For example, the working medium must be introduced intothe rotary machine from the periphery. If the working medium is very hotit heats up the housing one-sidedly and causes disvery many discs ononeshaft and owing to -increased losses in the blading. There isr alsothe important practical dimculty that the high temperature of theentering working medium are introduced near to the bearing.

InFlg. 4, therefore, discs b1 to bk and c1 to c4 carrying axiallyjuxtaposed radiallytraversed blading a1 to a4 are arranged on one onlyofthe two shaft ends 2 of another rotary machine (not shown) whilst onthe other shaft end are disposed rotary bodies 2lb and 25h-.carryingpacking 2l 4and 25 traversed by the driving medium which serve for theequalization of the axial thrust. The arrangement according to Fig. 4,therefore.

lrenders it possible to dispenser with the large transfer pipes and tofeed to the rotary bodies disposed on the one end of the shaft only somuch packed only against the low back pressure of the 'working medium.It is, therefore, possible to arrange the blading as well as the thrustequalizing device close to the bearings I, and the torque is transferredonly through oneend Vof the shaft,

the other end being relieved from the torque and thus available fordisposing auxiliary devices.

In Fig. 4 a larger number of blades than in Fig.

3 is distributedamong the same number of ro-` tatingdiscs4 b1, b2, bs,b4. According to thisj part of the invention, the bladings a1, az, anand a4 are hereb'y arranged in the most advantageous way, i. e. they areall traversed from the inner diameter outwardly.' Hereby an advantageousarrangement ofthe pressure equalizing discs 24a, 2lb. 25a, 25h with thelabyrinth 24, -25 on the same -shaft endwith the bladed discsisf-'rendered impossible. On 'the other hand a divisione of the bladingbetween the two shaft ends is not effected',y

whereby for lexample manufacture is` f made cheaper and the provision oflargetransfer'pipes together with the transference of-'torques throughboth shaft ends is avoided. The rotaryjf-t'r'iist equalizng discs areprovided on the-onheistaff* end where they are advantageously locatednear the bearing. Only a very small pipe 26 is provided for conveyingtothe second .shaft end the steam necessary-for the equalization ofthrust. Fig. 4 also shows the thrust bearing 21 necessary for takingupthe difference in thrusts.

The arrangement of pressure equalzing discs and the leakage losses ofworking medium caused by themmay in many cases be avoided in turbinesprovided with an action blading as shown in Fig. 5. Here the steamenters by pipes I2 and expands `to a comparatively low pressure in thenozzles 2l. The steam then implnges the action blades 22 whichcomprise-two velocity stages (Curtis blading) supported by the disc 28,and flows through the radially traversed blades 'a1, a2. a3 and theaxially traversed blades 8 leaving the machine through the exhaust portI5.

pressure on 'the discs b1. b2, ba an`d on the wheel 9 is small andeasily taken up through the shaft -2 by means of the' thrust bearing 21.This con.-

struction is especially suitable for small machines with low admissionpressure, as with the aid of axial. juxtaposition of severalconsecutively radially impinged discs according to the invention it ispossible in many cases-especially whenV action stages are'iirsttraversed-to diminish the. axial thrust to such an extent` -that it maybe taken up by a-thrust bearing 21 so that all losses of working mediumfor the purpose of thrust equalization may be avoided.-4 In order to beable `to'accommodate asuflicient number of discs on the shaft. ends theaxial thrust is equalized through the shaft 2 of the rotary machinewhich carries the discs in an overhungmanner. The

fthrust bearing 21'is accommodated on the other side of the rotarymachine from that which carries the discs in an overhung manner solthatl the whole space outside the bearing is available foraccommodation of the discs carrying the. bladesand packing.

In Fig. 6 the inventive idea is applied to a con- :lensing turbineinwhich the discs b1, ba, b3, b4, bs and 9 supporting the blades a1, az,an, a4, a5 and 8 are arranged on a special Iturbine shaft 2 between twobearings I according to'the standard practiceA with axially traversedturbines. The steam enters the housing H at lllflows. consecutively.through the blades al-as and l leaving the housing-gat l5. The totalaxialthrust created by the action of the steam on the discs F11-brandthe wheel 9 is taken up by the equalizing discs Ila with the labyrinthsIl. These equalizing discs are supported by the common bush." in orderto render accessible the discs bi-bs which are caulked directly totheshaft z The shaft 2 of the turbine may be coupled to a shaft 3| ofany VThe total thrust created by the action of the `low kind ofmachinery to `be driven by lmeans of the coupling 30.

The constructions shown have, of course, been I given by way of exampleonly, and the invention is not limited thereto.as various modificationsmay be resorted to within the scope of the apmeans o f a new method andapparatus for as semblingvand dismantling ythe machines and ofcorrespondingly constructed packing devices as described and claimed inmy copending application Serial No. 6\.-1,119. The packing devices I inFigs. 1-5 correspond tol the packing devices shown in said copendingapplication. 4In the =same way the discs b1, bz, etc. and the discs c1.cz.

etc. and the manner of fastening them correspond to the constructionsshown and claimed in my copending application Serial No. 600,500.

.By the expression reaction (steam or gas) turbine as used in thisspeciiication and in the appended claims, is to be understood a turbinein* which at leastvall of the rotating or all-of the stationary or allof the blade rows operate with reaction (the specially arranged `Curtiswheels bei-ng left` out of vconsideration in this connection). Theexpression the working` medium iiowing in the same general direction isintended to define the forward movement of the medium blades on each ofsaid discs. carrier rings supporting said blades at both ends thereof,and stationary bladed discs cooperating with said rotary discs, thelatter arranged to be impinged in series and on corresponding sides ofthe discs,

there'being apressure-drop through said blades and along said discs, themean pressures acting upon the opposite sides of at least certain ofsaid vdists beingn different and thus causing axial thrusts in thesamedirection,the number of rotary blades lbeing such that theycan bedistributed in additional rings on a smaller number of discs of largerdiameter without causing overstressing by centrifugal force acting onthe outermost rotating blades or on the disc or discs supporting themwhen the discs are driven at apprxirnately the rated speed of themachine, whereby the thrust on said discs is reduced, for a given totalpressurev drop, as compared with the thrust on discs carrying themaximum permissible number of rows of blades, rotary bodies on saidshaft, and.

packing devices disposed on said rotary bodies and traversed, by theworking medium and adapted to create a pressure drop of the workingmedium along said rotary bodies which equalizes the in the axialdirection, that is, the sequence in which the individual radial surfacesare swept by the medium one after the other. As will be apparent, theimpingement of a disc in a radially .outward direction corresponds to animpingement upon the opposite side of the disc with the direction ofimpingement reversed, that is,` radially4 inward toward the shaft.

l. In a. rotary machine, such as, a 'steam or gas turbine, thecombination of a shaft, bearings adapted to support said shaft, a drivenrotatingv machine .part arranged on' said shaft between saidbearingsprotary discs arranged o n a stubend of said shaft in overhungfashion, 'a number of radially traversed rows of reaction bladeson eachof said discs, carrier rings4 supporting said f blades at both endsthere-0f. and stationary bladeddiscs cooperating with said rotary discs,the latter impingedfin series. and on being arranged to be correspondingsides of the discs and there being a pressure drop through 'said bladesandV along said discs, the mean pressures acting upon' the oppositesides of at least certain o f said discs being different and thuscausing said discs in the saine direction,I

thrust of said discs, said discs being arranged on only one of the stubends of said shaft while the other stub end carries said rotary bodies.

3. In a combination comprising a rotary machine and a 'reaction steam orgas turbine for driving said machine and designed for operation at adenite. rated speed, 'a shaft, spaced bearings supporting said shaft, arotating element of said machine being arranged on'said shaftbetweensaid bearings, a plurality of discs disposed on a stub end of' saidshaft in an overhung fashion, rows of reaction blades arranged 'on soveach of said discs for radial traversal by a working medium andexceeding the number suitable for use in one Curtis stage, the number of.said

blades being such that they can .be Idistributed on a`smaller number ofdiscs of larger diameter without causing overstressing by centrifugalforce acting` on the outermost rotating rows `of blades or on the discor discs supporting them when the discs are driven at approximately,said

ra speedystaticnary bladed discs cooperating wi h said first-mentioneddiscs, a rotating wheel, blades adapted to be axially traversed arrangedon said wheel, said wheel being positioned between the bladed 'discs anda bearing, and a pressure equalizing disc for exerting an axial thrustin the 'direction ofthe bearings, said equalizing disc being arrangednextto said rotating wheel and beaxialthrusts upong the number ofrotaryblades being such" that they can be dis'- tributed on a smaller numberof discs of larger diameter without causing trifugal force blades or on.the disc or'disos supporting bycentween said bearings, rotary discsarranged on al stub end of said shaft in overhung fashion, more thanthree rows of radially traversed reaction -tween wheel and the bladeddiscs.

. 4`.Tne combination of t'wo rotary machines,

auch as avreaction steam or gas turbine and a machine thereby,vincluding a'shaft, bearings supporting said shaft intermediate its ends,

rotating parts of one of said machines arranged on said'shait betweensaid bearings, rotary discs when the` discs' are driven at approximatelythe l med on'both stub ends of said shaft in over" hung fashion,radially traversed rows of reactionblades on each of said discs, carrierrings supportin'g'said blades at both ends thereof, stationary bladeddises cooperating with said rotary discs, there being a pressure dropalong said discs mman ma blades, .conduits for leading the drivingmedium to said rotary'discs in `such manner that the mean preures actingupon the opposite sides oi' at least certain of said discs is differentand'causes axial thrusts upon said discs in the same direction, thenumber-of rotary blades being auch that they can be distributed on.additionolringsonamailernumber ofdiscsoi 'r 10ans? Y larger-.diameterwithout causing overstressing by centrifugal force acting on theoutermost rotating blades or on the disc or discs supporting them whenthe discs are driven 'at approximately the rated speed of the machine,whereby the total thrust on said discsis reduced. for a given total`-pressure drop, eompnred'witn the total thr'ust on fewer lbut largerdiscs carrying substantially' the same total number of blades.

4hung fashion, radially traversed rows of reaction blades on each ofsaid discs,-carrier rings support-v ing `said blades 'at both endsthereof, stationary blades discs cooperating with said rotary discs,there being av pressure drop through said blades, conduits for leadingthe drlvingmedium to said rotary discs in such manner that the meanpressures acting upon the opposite sides of at least certain of saiddiscs is different and ycauses axial thrusts' upon said discs in thesame direction, the -number of rotary blades being such that they can bedistributed in additional ringson a smaller number of discs of largerdiameter'without causing overstressingV by centrifugal force acting onthe outermost rotating blades or on the disc or discs supporting themwhen the discs are driven at approximately the rated speed of themachine,v whereby the total-thrust on said discs is reduced. for a giventotal pressure drop,I as compared with the total thrust on fewerbutlarger discs carrying substantially the same total number o1'blades,`

.and rotating wheels on said shaft carrying axially traversed blades,wheelsbeing arranged behind the last radially traversed blades and beingdisposed on both stub ends of said shaft betweenV t' the radiallytraversed discs and the bearings:

- 6; In a rotary machine, such as a reaction steam or gas turbine, ,thecombination of a shaft, rotating discs arranged on said shaft, aplurality of'radially traversed rows of blades 4ori each of said discsto be lmpinged by a working medium and exceeding the number suitable foruse in one 'Curtis stage, stationary bladed discs cooperating with-.saidmatins discs, end nnnuis elements supporting the rotating blades at bothends thereof, the pressure beingdiilerent lnat least each 1 second rowof said blades, the rotating discslbeing garranged to be lmplnged inseries and on corre-l sponding sides of the discs, the working flowingat diii'erent average pressures along the, two sides of atleast certainof said discs and in the saine general direction, thus exerting` axialthrusts upon shaft in thesame direction, said l. bladesbeing distributeda'mong such a number of discs who diameters are considerably less thanthe maximum permitted bylthefcentrlfugai force actin'g.f at the ratedspeed of the machine that the' blades of nt least one dise een bedisinbuted upon ,the einer discs withoutcausing their diameters teexceed said whereby the sum of the thrusts exerted upon the shaft isreduced for a' givenpressure op,ascon'ipared withthesum of the thrustson a smaller number of larger discs.-V

-'l. Themethodofreducingthetotaiaxialthrusto ,n a plurality of discshaving radiallyimpinged ofireactionbiades .at the corresponding indeslthereon-the rows exceeding the number suitable y for use in oneCu'tisstage, theaverage ,on the opposite sides of each disc beingdifferent tion.' which compris distributing the blades necessary toeffect the rrequired pressure drop through the machine upon'such anumber of `discs having outer diameters 'considerably below the maximumpermitted bythe 'centrifugal forces acting at the rated speed ofthemachine that the blades of at least one of the discs can be dis- 'andthe the-same directributed in an additional row or rows on the re`-maining without causing increase of the outer diameter of such discsbeyond-said xriaximum dian'ieter.-

8. Apparatus according td claim 6, wherein the mean diameterof saiddiscs increases 'from disc to disc in the 'general direction of the owof the working medium. 1 s

9. Apparatus according to claimV 6; wherein the .inner diameter of thediscs increases from disc to disc in the general direction oi' ow of theworking medium by at'least the radial width of one blade row.

1U. Apparatus according to claim 6. wherein the outer-,diameters oi thediscs increase from disc to disc in the general direction of now bfthevworking medium.

il. The combination according to claim 8,

wherein the sum of the axial thrusts created by the action of theworkingmedium-on saiddiscs is lequalized through said shaft' and takenup by oppositely acting mechanism at theiother end of said shaft.

I2. The combination 'according to claim 5, wherein said axiallytraversed blades are trav-f ersed in parallel. while .the blades iirstradially traversed by the `working medlum entering the machine aredisposed near the one,half of said axially andin parallel traversedblades-on the blades on the other stub end of said,

end. and means for conveying part of the working mediuii after furtherbut not yet complete transformation of energy at said other stub endback to saidi'lrst mentioned stubend, the transformation of theremaining .energy of theworking medium thus taking place st both' stubends.

i4. In a rotary machine, such as a reaction steam or gas turbine, thecombination of a shaft.

rotatingV discs arrangedon said shaft. a `plurality of radiallytraversed rows of blades on each of said discs to be impinged by aworking medium in the radial direction and exceeding the number fsuitable for Ause, in one Curtis' stage, stationary bladed discscooperating with said rotating discs. annular elements supporting therotating blades at both ends thereof, there being a pressure dro'p alongsaid discs through said blades, and conduits .ier leading ine drivingmedium to said rotary.

in such manner that the mean' pressures acting upon'the opposite' sidesorsi .least .certain o f said discs are diifer'entdand cause axialthrusts upon said discs'in' the same direction, the number of rotarybladesbeing such that they can bedis- /tribud on additions; rings on a`simmer number of discs of larger diameter without overlstressing bycentrifugal force acting on' outer,-

is .I

proximately the rated speed of the machine,

v whereby the total thrust on said discs is reduced,

for a given total pressure drop, as compared with the total thrustponfewer but larger discs carrying subnantially the same total number ofblades.

Patent No. 2,102,657.

CERTIFICATE or CORRECTION.

ULRICH MEININGHAUS 15. A rotary machine as set forth in claim 14 whereinthe diameters of the successive discs increase in the direction of fallof pressure of the working medium, the higher pressures thus acting ondiscs of smaller diameters.

umori nmININGHAUs. v

nagelneu:- 21, 1937.'

It is nerebyeer-mriee that er1-o1:-4 appeara ,in the' 'pzinseespecification' ef the above numbered patent requiring cerrectonlsfollews Psi-gre 9 second column; 1ne26, claim 11, for the claimreference 4rrurlierall "8"' read l; mid.v thet 'the said LettersuPatent: should be read with this'correctlbn therein that the same mayconform to the record eff-121:16 case'1n`the Patent Officer..

Signed and sealedths ist' day of March, A. D. 1958. l

(Sea1} Henry Van -Arsdn'1e Acting Comssionerof Patents.

proximately the rated speed of the machine,

v whereby the total thrust on said discs is reduced,

for a given total pressure drop, as compared with the total thrustponfewer but larger discs carrying subnantially the same total number ofblades.

Patent No. 2,102,657.

CERTIFICATE or CORRECTION.

ULRICH MEININGHAUS 15. A rotary machine as set forth in claim 14 whereinthe diameters of the successive discs increase in the direction of fallof pressure of the working medium, the higher pressures thus acting ondiscs of smaller diameters.

umori nmININGHAUs. v

nagelneu:- 21, 1937.'

It is nerebyeer-mriee that er1-o1:-4 appeara ,in the' 'pzinseespecification' ef the above numbered patent requiring cerrectonlsfollews Psi-gre 9 second column; 1ne26, claim 11, for the claimreference 4rrurlierall "8"' read l; mid.v thet 'the said LettersuPatent: should be read with this'correctlbn therein that the same mayconform to the record eff-121:16 case'1n`the Patent Officer..

Signed and sealedths ist' day of March, A. D. 1958. l

(Sea1} Henry Van -Arsdn'1e Acting Comssionerof Patents.

